Radek Zdonczyk

Cybersecurity guy · purple teaming · threat hunting · malware research

I'm curious about pretty much everything.

Radek`s notebook - professional cybersecurity, hardware hacking, a bit of SDR radio in spare time, learning and the countless ideas that develop from it all.

When an idea pops into my head and keeps me awake at night, I know I have to explore it further, no matter how much time it takes. Quite a few projects are waiting to be finished or to overcome the next barriers. Some of them I'll never finish. But I like to dig deep, sometimes off course, and those crazy things I stumble upon along the way are usually the best bit. I suppose it's this journey that says the most about me.

Over twelve years in cybersecurity; purple teaming, threat hunting and malware research, with a lot of time spent around Linux, networks and databases, running honeypots and turning what they catch into detection rules. After hours the same curiosity points at circuit boards, IoT and SDR radio: pulling firmware off flash chips, decoding protocols on the wire, working out what a device is actually doing under the plastic. Lately it is agentic AI security - instrumenting agents to see what they do at runtime, what they can automate, and building agent skills that triage malware and write detection rules. Most of the things and projects land on GitHub. RDN Security is where I write it up - ideas, dead ends, science, champagne and everything in between.